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By M. L. Bakker

The ISASMELT? top submerged lance (TSL) bath smelting process was developed in Mount Isa, Australia by Mount Isa Mines Limited (now a subsidiary of Xstrata plc) during the 1980s. By the end of 2011, the total installed capacity of the ISASMELT? technology will exceed 8 000 000 metric tons per year of feed materials in copper and lead smelters around the world. Commercial plants, operating in Belgium and Germany, are also batch converting copper materials in ISASMELT? furnaces. This TSL technology is equally effective for continuous converting processes, in which role it is called ISACONVERT?. This paper presents the recently patented ISACONVERT? process for the continuous converting of nickel and platinum group metal (PGM) containing mattes using the calcium ferrite slag system. The paper focuses on the potential application of the ISACONVERT? technology to existing nickel and PGM smelting complexes.

Jan 1, 2011

By A. G. Roach

Introduction The plant described in this paper is located at Coniston, Ontario, the smelting centre of the former Mond Nickel Company. Coniston is situated some eight miles east of Sudbury on the main line of the Canadian Pacific railway and on the Toronto-Capreol branch of the Canadian National-railways. The plant is now under control of the International Nickel Company, as a result of the merger of the two companies in 1929. The smelter proper includes four 50-in. by 240-in. blast furnaces and five 13 ft. by 30 ft. converters, and has a capacity of about 65,000 tons of ore charge per month. As accessories to the smelter there are a mill, where some 10,000 tons per month of low-grade ores are concentrated, and the sintering plant, which is the subject of this paper. The present 6-unit sintering plant replaces a former 4-unit installation. Here, fine ores, concentrates, and flue-dust are sintered on Dwight-Lloyd machines, the sinter produced being charged into the blast furnaces. At the time of writing (1931), only the concentrator is operating at capacity, due to present world conditions.

Jan 1, 1932

By R. Pallini

The Franklin Research Center (FRO, a Division of The Franklin Institute was contracted by the U.S. Department of Energy to investigate the application of elastomeric materials for the purpose of smoothing loads on dragline thrust rollers. This report covers the design, fabrication, and demonstration of a portable- device for measuring roller circle track deviations and roller loadings. The results of this work are documented in this report. During December 1981, a field test group visited the Falkirk Mine, Underwood, North Dakota for the purpose of demonstrating the use of the designed and built device. The data collected indicates the practicality and usefulness of such a device for determining actual dragline roller circle roller loads, while the dragline is in service. The device was useful in determining roller load peaking that may be a contributing Factor in the premature failure of these thrust rollers. The device could be used for field evaluation of elastomeric cushioning materials used to eliminate these load peaks.

Jan 1, 1982

By M. Fan

Coal has in general a wide range of density from minus 1.3 to plus 2.0 g/cm3 because of its variations in purity, rank, and porosity, etc. The coal density has great impact on froth flotation performance, but much less attention has been paid to particle density than particle size. Our previous research results demonstrated that cavitation-generated nanobubbles around 700 nm in diameter can significantly improve coal and phosphate flotation performance over a wide particle size range. In this study, the effect of nanobubble on the flotation performances of different density fractions (minus 1.3, 1.3-1.4, 1.4-1.5, 1.5-1.6, 1.6-1.8, 1.8-2.0, 2.2-2.2, and plus 2.2 g/cm3) of coal was investigated using a bank of 10-liter flotation cells, a specially designed 50-mm-inside-diameter column, and a 152-mm-inside-diameter column. It was found that nanobubble has the biggest impact on the flotation performance of 1.4-1.8 g/cm3 medium-density coal particles.

Feb 23, 2014

By Edwin C. Reeder

This paper, describing milling methods and costs at the Hillside Fluorspar Mines at Rosiclare, Ill., is one of a series being prepared for and published by the United States Bureau of Mines on non-metallic milling methods. The milling practice described is that of one of the large mines in the Kentucky-Illinois fluorspar field in southern Illinois and western Kentucky, on the Ohio River. Milling methods throughout the district are similar in their general principles, although details vary considerably in different plants.

Jan 1, 1932

By W. Greg Maybee

Separations, which form along stratigraphic boundaries in the roofs of potash mines, pose a serious safety concern. If these separations go undetected they can lead to falls of ground. The current method of identifying the location and extent of these separations is through manual scaling (sounding) using an aluminium rod. The potash mining companies would like to have a tool, which could quickly and reliably detect these separations and distinguish between them and clay seams. This paper presents the results of field trials undertaken at various potash mines in Saskatchewan belonging to the member companies of the Saskatchewan Potash Producers Association. A ground penetrating radar instrument from RST called SUSI (stepped frequency, ultra-wideband, synthetic aperture radar instrument) was used. SUSI has the ability of working over various frequency bandwidths. Four mines were chosen for these field trials, covering the different geological characteristics encountered in the Saskatchewan potash mines: Potash Corporation of Saskatchewan?s (PCS) Allan and Lanigan Divisions, Agrium?s Vanscoy Potash Operations and IMC Potash?s K2 Mine. These field trials indicated that stepped frequency ground penetrating radar technology could be ?tuned? to identify both separations and clay stratigraphy in the softrock, potash mine environment, based on the different spectral responses of the features.

May 1, 2004

By Sathit Tandanand

Horizontal displacements and ground strains induced by mine subsidence are significant information needed for calculating damage and developing precautions against subsidence effects on surface structures. To devise a simple method for determining the surface horizonal displacements and strains simultaneously with the subsidence prediction, the U.S. Bureau of Mines examined the significance of the tilt number, which is the proportionality constant in the relationship between the horizontal displacement and the slope of the subsidence profile. The ratio of the tilt number to the critical radius of the subsidence trough is identical to the ratio of the maximum possible horizontal displacement to the full subsidence, which is found to be constant in most European coalfields. If this ratio is known for a particular minesite in the United States, then horizontal displacement and ground strains can be readily obtained from the primary subsidence data.

Jan 1, 2010

By G. S. Rice, J. W. Paul, M. W. VONBERNEWITZ

This bulletin abstracts and reviews essential details of reports on 59 fires in different coal mines in the United States, describes the circumstances of origin and the methods of controlling or extinguishing the fires, and points out the lessons taught. all, the fires caused great damage to property and killed nearly 400 men. The data have been compiled from the records of the Bureau of Mines, which cover most of the major mine accidents in the United States since 1.908. The names of the mines concerned and of the persons connected with the management of those mines have been omitted in accordance with the usual policy of the bureau. The bureau hopes that this bulletin will be of service to all persons interested in lessening the fire hazard at coal mines and to all who may be called on to fight a mine fire.

Jan 1, 1927

By Simon D. Strauss

This article is part of a presentation Strauss made Dec. 3, 1988 at the sixth annual American Mining Hall of Fame (AMHofF) banquet in Tucson, AZ. At the banquet, the Mining Club of the Southwest honored Strauss by naming him the 1988 recipient to the AMHofF. (Industry newswatch, page 6). Introduction In the last two decades, there have been two previous periods of sharply rising copper prices. One was in 1973-74; the other in 1979-80. In both cases, a short period of high copper prices was followed by steep and prolonged periods of low prices. In the language of the market analyst, the high prices were called spikes. Is it likely, then, that three or four years from now the present price of copper will show up as a spike in the charts? There are substantial differences between the current position and the markets of 1973-74 and 1979-80. In 1973-74, US copper prices were subject to government-imposed price ceilings of $0.60 per lb through early December, 1973. These were increased to $0.68 per lb through May, 1974. Meanwhile, mines outside the United States were free of restraint. Rising demand in London pushed the price above $1 per lb in the third quarter of 1973. In early April 1974, it reached a peak of $1.50 a lb. In May of that year, the US ceilings were removed and the domestic price began to rise. What were the causes of this price strength? While ceilings held the domestic price below the world market, domestic consumers acquired all the tonnage offered by US mines. Meanwhile, in the world market, buyers feared prolonged shortages. The Club of Rome had warned that world economic growth would be limited by impending depletion of mineral resources. There was al so concern about a copper cartel that might increase copper prices even more. In early 1974, at a special United Nations session, developing-country spokesmen warned the industrialized world to expect high commodity prices. Also adding to the concerns of copper buyers was the fear that when US wage contracts expired in mid-1974, protracted strikes might ensue. The combined effect of this atmosphere was that consumers accumulated large amounts of copper, far above their normal carry. By midsummer, the position changed radically. While some strikes did occur in the United States, they proved short-lived. The most significant development was a massive economic recession. The energy crisis was causing enormous dislocations in the world economy. Construction activities were sharply reduced and automobile sales plummeted. Public confidence was shaken. Copper sales fell precipitately as consumers decided to draw down their swollen inventories. The price came down too. In April 1974, the London price- as noted-was $1.50 per lb. By the end of the year, it was down to $0.57 per lb. In 1973-74, the copper price rise was fed by fears of shortages, cartels, and strikes. In 1979-80, the market rose on the strength of good demand plus political and military instability. The price rise was also fed by inflationary trends, exemplified by speculation in precious metals. Prior to this second spike in copper prices, the market had been depressed despite economic recovery. Despite reduced US output, copper production in the rest of the world was increasing. Though consumption was rising, surplus stocks reached unprecedented levels. At the end of 1977, the aggregate of stocks at the refineries and in the exchange warehouses was 1.5 Mt (1.67 million st). That was more than three months' shipments at then rates of consumption. In 1978, the statistical position improved. Shipments of refined copper that year were 8% greater than in 1977. The result was reduced visible stocks but -just as was to be the case in 1984-86 - the price remained depressed. In 1979, an even sharper drop in visible stocks occurred as shipments rose by another 4%. This time, though, the price responded. In December 1978, the price in current dollars had been less than $0.70 per lb. By the end of 1979, it was above $1 per lb. And in the first quarter of 1980, it averaged more than $1.20 per lb. Military and political developments were a factor. The hostage crisis in Iran was followed by the Soviet invasion of Afghanistan. To many, it appeared that war might result if the Soviets pushed on into Pakistan. At the same time, speculation drove gold and silver prices to incredible levels. As silver prices rose above $40 per oz), copper above $1 per lb did not seem unreasonable. Then, in March 1980, the precious metals price boom collapsed. Copper prices also retreated, though not as much. In February 1980, the copperprice averaged $1.32 per lb. By December, it had dropped to $0.85 per lb. In 1981 and 1982, the decline continued. The present copper situation Why is the current situation different from these two previous episodes of high prices? First of all, today's inventories are far lower than they were in either 1974 or 1980, when the price declines began. The stocks at refineries and in exchange warehouses are substantially less than they were then. More significantly, consumers today have very limited holdings compared with stocks they carried in 1974 and 1980. Even if faced with a downturn in their own business, copper consumers will not be able to stay out of the market. To the extent they have any business at all, they will have to buy copper. And on the supply side, there is also a significant difference. The year 1988 has been unusual. US production is up sharply, responding to higher prices. But production is little changed in the rest of the Free World. Indeed, several of the major producing countries have mined less copper this year than in 1987 despite the prices increases. Peru has had labor problems that have cut its output. Zambia and Zaire suffer from shortages of expatriate technicians, not to mention spare parts. They also suffer from the failure to maintain equipment or perform adequate development. In Chile, the two largest mines, Chuquicamata and El Teniente, have not met their production targets. Chuquicamata is struggling with high arsenic content in its ore. And, in late 1987, severe rockbursts hampered operations at El Teniente. In addition, depletion of some mines in Australia and South Africa has offset rising output at other properties. Indeed, when final mine output figures for 1988 become available, it may well be

Jan 1, 1989

By Anthony T. Xannacchione, Luis E. Vallejo

At present, there is little knowledge concerning the shear strength of clays containing floating rock particles with concentrations from 0 to 30%. In practice, the effect of rock particles is typically disregarded in shear strength analysis The two primary reasons for this are: 1) a lack of agreement concerning the influence of rock particles on material strength, and 2) the expense and difficulty of testing day-rack mixtures with existing laboratory procedures. These factors have impeded the development of successful slope remediation design techniques far colluviums derived from resistant sedimentary rocks or spoil produced from surface mining. This study reviewed 3 1 technical papers which contain analysis of shear strengths for clay and sands with varying mixtures of rock particles. These technical papers, published over the last 40 years, are comprised of field case studies, laboratory evaluations, and theoretical analysis. Evaluation of this body of knowledge ha shown that the shear strength gradually increases with increasing percentages of floating particles in unsaturated clays.

By M. Pillay

INTRODUCTION Heat stress continues to be a safety concern in underground mining. This is due to a number of reasons including increasing depths of mining, increased levels of heat generated from machines, ventilation systems being constrained from providing suitable levels of airflow and others. In order to assess if a thermal environment is safe for miners under normal or modified work arrangements, or to specify stop work conditions a heat stress index is used to guide decisions. Historically, a number of heat stress indices have been developed and applied in underground mines. These can be classed under three broad headings; single measurement, empirically based and rational indices. Do any of these indices perform better than the others? Which one allows simple determinations and decisions to be made in the mine? This paper aims to provide answers to these questions by comparing and contrasting three indices; effective temperature (ET), simple air cooling power (ACP) and Thermal work limit (TWL) for a range of typical mining wet and dry bulb combinations? The paper concludes with the identification of areas for future research. BACKGROUND Heat stress causes discomfort, increases physiological strain, decreases productivity and performance, and contributes to increased incidents [1]. Effective management and control of heat stress is particularly important in mining where hot working conditions are very common [2]. Heat stress index is a common indicator that is used by mine safety advisors and managers to guide decisions about safe work practices in mining under normal or modified conditions. According to Howes and Nixon [3] A safe heat stress control strategy for an underground mine has three elements: • Application of an environmental measure which reflects physiological strain with sufficient accuracy for the range of conditions encountered underground. • Acceptance of a functional relationship between the environmental measure and human performance which is used to optimise the environmental conditions achievable with either ventilation or ventilation and refrigeration. • A management control strategy based on the environmental measure which is designed to ensure that work in environments where excessive physiological strain may occur is prevented and corrective action is initiated. The link between these elements is an environmental measure that reflects the physiological strain a worker is subjected to. Since the turn of the twentieth century various indices of thermal stress have been developed (McPherson [4], Howes and Nixon [3], Brake [5]). In selecting a suitable environmental measure or index one problem that must be addressed is the ease with which it can be physically obtained relative to it accurately reflecting the physiological strain. No index can be universally applied and there is no single correct measure or index. However if an index has provided adequate control in a particular circumstance, then it can be regarded as correct for that situation.

Jan 1, 2019

By C. T. Sheeran

The Bureau of Mines investigated a microprocessor-based real-time control and monitoring system for uranium mining applications. The system is capable of controlling and monitoring up to 768 stations within 3 km of the central processor on a common four-wire cable. It can be used in conjunction with detectors to continuously monitor and display radiation working levels at points throughout the mine. Surface alarms are sounded for critical situations such as rapid radiation buildup, loss of power to monitors or fans, and changes in air door position. Permanent records of all changes are automatically printed out with their time of occurrence. Printouts can also be obtained for shift reports or trend logs. The system can be used to remotely control fan startup and shut-down, and also can alert miners of underground conditions by blowing horns or turning on lights. Battery backup keeps the system operative for up to 4 h in case of a mine power outage. A special software feature permits automatic, time-delayed, sequential restart of fans.

Jan 1, 1984

By Herbert Hoover

YOUR committee asks that I speak today on the relations of the engineering profession to public affairs. That takes in a lot of ground. This being a cheerful occasion, I will assume that I should exclude the engineer's function as a taxpayer. This being a nonpartisan occasion, I will assume that I should not refer to his voting emotions in 1940. Perhaps what was in the minds of your committee was the application of engineering thought to the confusions of the times. That is also a lot of ground. I fear, however, its boundaries disappear in mirages and rainbows on all sides. Now any entry of the engineer into public affairs involves his breaking into the fields of the sociologists, the economists, and the politicians. However I don't know why, seeing the difficulties these professions are having, they should not welcome a little help.

Jan 1, 1939

By M Runkel, J Hammerschmidt, A Holmstr÷m, A Charitos, J Gnntner

"Roasting of sulfide concentrates and refractory ores is an important process step in the production of metals and chemicals. Sulfides of iron, zinc, copper and other metals are oxidised with air between 600 and 1000¦C into metal oxides or sulfates and gaseous sulfur dioxide. Roasting of gold concentrates and ores is a typical processing step used to produce a porous calcine suitable for cyanide leaching. During roasting, elements posing problems are removed through: oxidation (carbon, sulfur, arsenic and antimony) or volatilisation (mercury, chlorides and tellurides, as well as arsenic and antimony).This paper focuses on the environmental aspect of roasting using fluidised bed technology. The approach is to show that roasting is an attractive solution for refractory ore pretreatment since, on the one hand, it is an efficient technique yielding high gold recovery rates, while on the other it is able to comply with current stringent international environmental regulations. In that respect, roasting is compared to alternative processes, ie pressure oxidation (POX), bio-oxidation (BIOX) and ultra-fine grinding (UFG). Roaster high gold recovery rates are ensured through roasting-leaching test work, which allows the derivation of respective roasting parameters that are easily achieved in an industrial plant. On the other hand, key elements of the roasting process are analysed, which make it an efficient and sustainable technology, ie the possibility for energy recovery, the removal of off-gas impurities during the different gas cleaning steps (handling of arsenic, mercury emissions and further hazardous dust and gas emissions) and the treatment of the SO2-gas in order to produce sulfuric acid, and finally the treatment of the effluent produced. The processÆs environmental aspects are summarised by listing roasting emission values that comply with international regulations.CITATION:Charitos, A, Runkel, M, Gnntner, J, Holmstr÷m, A and Hammerschmidt, J, 2013. Roasting - a study on environmental aspects, off-gas, effluents and residue treatment, in Proceedings World Gold 2013, pp 509-518 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 26, 2013

By S. Nikolic, G. M. Stieper, D. P. Mallah, B. J. Hogg, P. B. Voigt

Copper feed materials processing is becoming more challenging, due to an incremental increase in the mineralogical and compositional complexity of these feeds. These complex and polymetallic feeds are now becoming more common and many sites have been forced to re-evaluate their operating strategies to process these materials at cost competitive rates, whilst meeting ever more stringent environmental regulations. Most operations must first evaluate the merits of pyrometallurgical and hydrometallurgical treatment routes. Although there are multiple copper smelting technologies available, only top-submerged lance (TSL) technology, supplied by Glencore Technology as ISASMELT™, has been applied in the real world to consistently and successfully smelt complex materials in integrated metallurgical facilities such as Glencore’s Kazzinc Ltd. operation in Kazakhstan, Umicore Precious Metals Refining in Belgium and Aurubis AG in Germany. Glencore Technology also offers hydrometallurgical processing, through the Albion Process™ technology, opening up viable flowsheet options previously not possible for these complex feeds. This paper describes a number of real world process flowsheets at global operations and Glencore’s own operations at Mount Isa and Kazzinc Ltd., which process complex feeds. These flowsheets integrate the ISASMELT™, Albion Process™, ISACONVERT™, ISAKIDD™ Tank house, and bottom blown oxygen cupel (BBOC™) technologies to provide an effective process solution for the treatment of complex polymetallic feeds to produce metallic copper and associated by-products. INTRODUCTION Traditional smelters and those built in recent times within the bulk smelting hubs of the world have been designed to treat standard/clean concentrates. In recent years the processing of complex polymetallic sulfide concentrates and the recycling of secondary copper and derivatives of waste electrical and electronic equipment, such as e-scrap, have become a focus for numerous companies (Alvear & Nikolic, 2013). Processing of these complex feeds, characterized by relatively high levels of minor elements (over 5% of elements such as arsenic, antimony, bismuth, lead and zinc) is more challenging. Facilities not designed for these types of materials may require significant modifications or a change in smelting technology to treat them. Often operations find themselves re-evaluating the merits of pyrometallurgical and hydrometallurgical treatment routes for their sites through a number of factors:

Jan 1, 2019

By Eugene H. Skinner

The U.S. Bureau of Mines conducted experiments on the use of lightweight concrete in the density range of 100 Ib/ft3 for liners in underground mines. Three test sections were completed: a monolithic, portal-type structure with integral walls and arch constructed aboveground; an underground test section constructed in a mine drift using plywood forms; and a second section constructed in a drift using an air-supported formwork. The lightweight concrete in the two underground test sections was placed using piston pumps and a slickline. Fiber reinforcement was added to the concrete in the mine sections without any apparent problems with either pumping or placement of the concrete. In another experiment, the Bureau and Hecla Mining Co., Mullan, rD, used lightweight concrete in the density range of 25 Iblfe to replace timber blocking in a raise preparation structure. Other experiments are described in which low-density, lightweight concrete blocks were produced for mine ventilation doors, stoppings, and barricades. Other mine uses reviewed include pillars and collapsing beams. An advantage of low-density concrete is that it will display up to 50% deformation at a constant yield stress. These hlllovative concepts in deformable concrete lining systems will aid mine operators by decreasing capital and maintenance costs, increasing the available space in underground haulageways, and providing productivity gains and improved resource recovery in the soft, caving, squeezing, or bursting grollnu conditions often found in deep mines.

Jan 1, 1989

By S. L. Ausmus

The work covered in this report is a continuation of an earlier feasibility study by the Federal Bureau of Mines and points out improvements in the skull-melting method for casting reactive metals such as titanium, zirconium, and hafnium. Machined graphite molds with laminated sections can be reused many times. Large tube sections can be produced by spin casting. Graphite powder is the best expendable mold material, but binders for this use must be compounded carefully. The effects of current and furnace atmosphere on the dependent variables of the casting technique are shown. Because of developments in casting technology for titanium which eliminate the basic problems of melting and pouring the metal, opportunities for improvement in the method have increased. The mold material and gate and riser configurations require particular attention. The limits of application of the casting method have yet to be defined. New knowledge in anyone of these areas could result in marked improvements and simplifications in casting methods.

Jan 1, 1960

By J. F. Wilson

An experimental investigation has been made of gas-driven slug displacements in a system of high gas saturation to evaluate the process for use in a California reservoir. Fluid compositions, temperature, pressure and core permeability duplicated reservoir conditions as closely as possible. The temperature was above the critical of the slug materials. The slug composition required for 100 per cent oil recovery in the linear flow systems was found to agree with that determined from equilibrium phase studies. A qualitative theory for the slug displacement of two-phase systems is proposed and found to be in general agreement with the observed flow behavior. The theory predicts that the length of the reservoir fluid-slug transition Zone will increase with increased initial gas saturation and decrease with increased oil swelling accompanying the composition change from reservoir oil to the critical composition. The precipitation of small amounts of an asphaltic phase during the formation of the transition zone had no adverse effects on the flow behavior of otherwise miscible systems. INTRODUCTION Despite the large number of recent publications relating to oil recovery by miscible displacement, little information is available concerning the behavior of crude oil-natural gas systems at conditions likely to be encountered in field application. The laboratory data reported here were obtained during an investigation of the possibility of using a gas-driven LPG slug in a partially depleted California reservoir. Seven gas-driven slug displacements employing slugs of different compositions and sizes were made in 26- to 27-ft long sandstone cores. The equilibrium phase behavior of the systems was also determined. The features of primary interest in this study are the following. 1. Data were obtained on the displacement of reservoir fluids at reservoir conditions. 2. A high gas saturation existed in the long cores at the start of the displacements. 3. The temperature of the studies was above the critical of the slug materials. 4. A comparison between the flow behavior and equilibrium phase behavior, as illustrated by a pseudo-ternary phase diagram, is afforded for a system of considerable complexity. THEORY Phase Behavior The use of the pseudo-ternary phase diagram to illustrate the phase behavior in miscible displacements has been discussed by Clark, Schultz and Shearin. Sie-vert, Dew and Conley and Arnold, Stone and Luffel' have presented both phase equilibrium and flow data for true ternary systems. For the true ternary, the application of the theory is straight-forward; for a reservoir system represented as a ternary, the theory undoubtedly gives a qualitatively correct picture. One purpose of this investigation was to see if the pseudo-ternary phase diagram could be used to predict with reasonable accuracy the conditions necessary for miscible displacements with actual reservoir systems. MiscIBLE Displacement of Two-Phase System A large number of papers "I3 have treated the miscible displacement of a single-phase fluid from both an experimental and a theoretical viewpoint. However, the normal field application of the process will be in a partially depleted reservoir. Often the state of the system will be such that the mobility of the gas phase is greater

By E. R. Bauer

This report presents the results of a cooperative study between BethEnergy Mines Inc., Ebensburg, PA, a central Pennsylvania coal mining company, and the U.S. Bureau of Mines to investigate longwall development entry roof instability. In-mine mapping of geologic and deformational features was conducted to reveal the major ground control problems encountered during gate road development. In addition, mining-induced pillar load monitoring was used to indicate development loading on variously dimensioned gate road pillars and to determine if pillar yielding occurred. Finally, visual observations of a variety of roof control methods were used to determine the most effective support elements for controlling cutter roof failure.

Jan 1, 1992

By Brendan Demich, Joseph McGuire, Emily J. Haas

Near misses recorded and reported by workers can provide awarenessto the potential causes of injury and prompt safety management initiatives. Although most companies require near-miss reporting, it is unclear what the value of these reports are, if any, and how they influence subsequent actions or controls to reduce on-the-job risks. Researchers at the National Institute for Occupational Safety and Health (NIOSH) conducted a case study with an aggregates company in which near-miss reports were analyzed at each of their locations over an entire quarter during the summer of 2018. Within that quarter, workers recorded 249 near misses. Of those, 167 were valid near misses that occurred at work. Researchers coded the reports using a qualitative 5 × 5 risk matrix. Of the 167 near misses, 19% were deemed low risk, 25% moderate risk, 30% high risk, and 26% critical risk. Several patterns in the near-miss incidents were documented, including classification of incidents and common corrective actions referenced (i.e., elimination/substitution, engineering control or redesign, work process/procedures, and personal protective equipment). The analysis provides insight into ways that risk communication and management programs can be improved to reengage workers and their situational awareness on the job.